Apparently, the ListView does not have a SelectedIndex property that can be set.
Indeed, this is logical, as you can select multiple items.
Therefore, it has a property SelectedItems, as well as a property SelectedIndices; both are read-only.
Selected true:
listView1.Items[someItemIndex].Selected = true;
ListView MultiSelect false, . , .
, listView1.SelectedIndices.Clear(); listView1.SelectedItems.Clear();..